[0001] This invention relates generally to a parking brake system for a motor vehicle. More
specifically, the present invention relates to a force reversing and transmitting
apparatus for use therein.
[0002] U. S. Patent No. 4,212,211 discloses a conventional hand operated parking brake actuator.
Typically, the actuator is mounted to a floor member within easy reach of the vehicle
operator. The actuator transmits the operator's input force on the handle of the actuator
to an output force at a cable attachment on the actuator, thus resulting in a tension
force in a cable linkage. The cable linkage transmits the tension force to engage
a set of rear wheel brakes. The cable linkage in a conventional parking brake actuator
design runs directly rearward from the cable attachment at the actuator toward the
wheel brakes.
[0003] In the design of an electrical vehicle, economical adaptation of a conventional parking
brake actuator presents challenges previously not encountered. An electric vehicle
carries a battery for a source of energy. The size, shape and mass of the monolithic
battery requires a structurally unencroached mounting location within the vehicle
structure. Typically, the most feasible location for the battery is under the cargo
floor, immediately rearward of the operator seating area. This conflicts with use
of a conventional hand operated parking brake actuator, since the conventional actuator
requires routing the cable linkage directly to the rear of the brake actuator and
therefore, the cable linkage would encroach the battery package space.
[0004] It would be desirable to provide an apparatus that would allow the use of a conventional
parking brake actuator in battery powered electric vehicles.
[0005] According to the present invention, a parking brake apparatus is disclosed for use
in a motor vehicle, the apparatus being mounted on a floor member of the vehicle,
to operatively connect a hand-operated brake actuator to a wheel brake. The parking
brake apparatus comprises link means for reversing and transmitting an output force
from the brake actuator to a tension force at the wheel brake. The parking brake apparatus
further comprises bracket means for mounting the brake actuator to the floor member
and cable means operatively connecting the link means to the wheel brake.
[0006] One advantage the present invention provides is the use of a conventional parking
brake actuator in a vehicle in which the cable means projects from the front of the
actuator to engage the wheel brakes. These and other objects and advantages of the
present invention will become apparent from the drawings, description and claims which
follow.
[0007] The invention will now be described further, by way of example, with reference to
the accompanying drawings, in which:
[0008] FIG. 1 is a perspective view of a motor vehicle having a parking brake apparatus
according to the present invention.
[0009] FIG. 2 is an elevational view of a parking brake apparatus according to the present
invention.
[0010] FIG. 3 is an elevational view of a parking brake apparatus in a brake-released and
brake-applied position according to the present invention.
[0011] Referring now to the figures, FIG. 1 illustrates a motor vehicle 10 having a parking
brake apparatus according to the present invention. A hand operated brake actuator
12 is supported on a floor member 18 of the motor vehicle body structure 16. The brake
actuator 12 operatively connects a left 20 and right 22 rear wheel brake by cable
means 24. A battery 26 mounts to the underside of the body structure 16 between the
brake actuator 12 and the left 20 and right 22 rear wheel brakes.
[0012] FIG. 2 illustrates the parking brake apparatus of the present invention with the
brake actuator 12 elevated a predetermined distance above the floor member 18 by bracket
means 14. The brake actuator 12 translates an input force exerted by the operator
on actuator handle 32 to an output force at camming pin 34. It should be readily apparent
to one skilled in the art that many types of brake actuators exist having the same
operability and utility.
[0013] As further shown in FIGS. 2 and 3, the parking brake apparatus includes link means
36 comprising an elongate link member 38 operatively interposed and connecting the
brake actuator 12 to the cable means 24. The link member 38 has an upper end 40 and
a lower end 42 and attaches to the bracket means 14 with a pivotable fastener 44.
The upper end 40 of link member 38 forms a camming surface 46 for engagement with
the camming pin 34. The camming surface 46 comprises a U-shaped slot, however, the
present invention is not so limited. Many configurations would function equivalently,
such as a V-shaped slot or an oval aperture. The lower end 42 of link member 38 operates
as a cable fastener 48. The cable fastener may comprise, but is not limited to, a
pinned joint or a threaded rod fastener.
[0014] The bracket means 14 includes first 50 and second 52 brackets mounted to the floor
member 18 to elevate and support the brake actuator 12. Additionally, the second bracket
52 includes a cantilevered, pivotable fastener 44 which engages the pivotable fastener
44 of the link member 38. The height of the bracket means 14 determines the clearance
for link member 38 rotations from a brake-applied position 54 to a brake-released
position 56. It should be readily apparent to those skilled in the art that various
designs would serve the purposes of the bracket means stated herein. For example,
the design could include, but is not limited to, having the actuator 12 mounted directly
to the floor member 18.
[0015] Referring back to FIGS. 1 and 2, the cable means 24 includes first 58 and second
60 cables operatively connected to the respective left 20 and right 22 wheel brakes.
The first 58 and second 60 cables extend forward (to the front of the vehicle) from
the respective wheel brake along the outboard sides of the body structure 16. At a
predetermined point forward of the front edge of the battery 26, the cables 58 and
60 bend laterally inboard and extend rearward to connect to an equalizer 62 at a point
forward of the brake actuator 12. A third cable 64 attaches the equalizer 62 to the
pivotable fastener 44 disposed on the lower end 42 link member 38.
[0016] In operation and as shown in FIG. 3, the vehicle operator engages the parking brake
by raising the actuator handle 32 of the brake actuator 12 from the released position
56 to the applied position 54, which ultimately creates a predetermined tension force
in the cable means. As the actuator 36 is rotated upward by the operator, the output
force at the camming pin 34 acting on the camming surface 46 is directed toward the
front of the motor vehicle 10. The link member 38 rotates on the pivotable fastener
44. The reaction force 68 at the lower end of the link member 42 pulls the cable means
24 toward the rear of the motor vehicle 10. The cable means 24 directly transmits
the resultant tension force to the respective left 20 and right 22 wheel brakes.
1. A parking brake apparatus for use in a motor vehicle, the apparatus mounted on a floor
member (18), for connecting a hand-operated brake actuator (12) to a wheel brake (20,22),
said parking brake apparatus comprising:
link means (36) for reversing and transmitting an output force from said brake
actuator (12) to a tension force at said wheel brake;
bracket means (14) for mounting said brake actuator (12) to said floor member (18);
and
cable means (24) operatively connecting said link means (36) to said wheel brake
(20,22).
2. A parking brake apparatus according to Claim 1, wherein said link means further comprises:
an elongate link member having an upper and a lower end;
actuator;
link member for slidably engaging said camming pin;
to said bracket means at a point disposed approximately between said upper and
said lower end of said link member; and
link member for fastening said cable means to said link member.
3. A parking brake apparatus according to Claim 2, wherein said camming surface comprises
an U-shaped slot.
4. A parking brake apparatus according to Claim 2, wherein said link is angularly displaceable
from a brake-released position to a brake-applied position.
5. A parking brake apparatus according to Claim 2, wherein said bracket means further
comprises a first and second bracket adapted to raise said brake actuator a predetermined
distance above said floor member to allow clearance for said link member to rotate.
6. A parking brake apparatus according to Claim 5, wherein said second bracket further
comprises a cantilevered pivot for pivotably fastening said link member to said second
bracket.
7. A parking brake apparatus according to Claim 1, wherein said cable means further comprises:
an equalizer;
a first and second cable each operatively connected, respectively, to a right and
left rear wheel brake, each of said cables connecting to said equalizer; and
a third cable interconnecting said equalizer to said link means.
8. A parking brake apparatus according to Claim 7, wherein said cable means extends forward
from said wheel brakes along respective outboard edges of said vehicle to a predetermined
location, thereupon bending laterally inboard and extending rearward to connect to
said link member.
9. A parking brake apparatus for use in a motor vehicle, the apparatus mounted on a floor
member, to operatively connect a hand-operated brake actuator to a wheel brake, said
parking brake apparatus comprising:
actuator;
said floor member;
lower end for reversing and transmitting an output force from said brake actuator
to a tension force at said wheel brake, said link member further comprising:
said link member for slidably engaging said camming pin;
member to said bracket means at a point disposed approximately between said upper
and said lower end of said link member;
said link member for fastening said cable means to said link member; and
to said wheel brake, said cable extending forward from said brake along an outboard
edge of said vehicle to a predetermined location, thereupon bending laterally inboard
and extending rearward to connect to said link means.